The new 120i engine will be as follows, so it would seem to be a reasonable assumption that future 320i's will also get it:

120i: New four-cylinder engine with high-precision direct injection and Bi-VANOS technology achieves zero to 62mph in 7.7 seconds (7.8 seconds for five-door) before going on to a top speed of 139mph. Output is 170hp (up 20hp) while peak torque is now 210Nm (up 10Nm). Combined fuel consumption is 44.1mpg (improves by 17 per cent), CO2 emissions are 152g/km (down 16 per cent).